Gruden, 54, last coached in the NFL in the 2008 season for the Tampa Bay Buccaneers. His new contract with the Raiders is for 10 years and likely approaching $100 million, sources previously told ESPN's Adam Schefter, which will take him with the franchise to Las Vegas in 2020.

The announcement comes nearly 20 years to the day when Gruden was first introduced as the Raiders' coach. He served in that role from 1998 through 2001, before being traded to Tampa Bay. His Buccaneers beat the Raiders 48-21 in Super Bowl XXXVII.

This time Gruden will replace Jack Del Rio, who went 25-23 in three seasons with the franchise.

Gruden's return to coaching ends his nine-year stint with ESPN.

"It's an emotional and bittersweet day for our Monday Night Football family, as today we say goodbye to Coach Gruden after nine very distinguished years coaching this Monday Night Football group," ESPN analyst Sean McDonough said at the beginning of Saturday's game.

Perhaps fittingly, Gruden's last Monday Night Football broadcast came in Kansas City, the home of the Raiders' biggest division rival.

"These Chiefs fans have been on my case since we got here," Gruden said jokingly.